Fire-box for boilers.



- UNITED STATES Patented June 30, 190.

PATENT OFFICE.

WILLIAM ILLAUGHRIDGE, OF COLUMBUS, 01110, AssIcNoR on TWO- THIRDS TO STEWART s. STIFFEY AND MAURICE s. coNNoRs, or

COLUMBUS, OHIO.

SPECIFICATION forming part of Letters Patent No. 732,643, dated June 30, 1903.

Application filed March 2, 1903. Serial No. 145,790. (No model.) i

To all whom/it may concern.-

Be it known that I, WILLIAM H. LAUGH-' RIDqE, a citizen of the United States, residing at Columbus, in the county of Franklin and State of Ohio, have invented new and useful Improvements inFire-Boxes for Steam-Boilers, of which the following is a specification. This invention relates to a fire box for steam-boilers; and the object of the invention is to provide simple and efiective means for compensating for the expansion and contraction in the fire-box sheets, to prevent cracking and bulging of said sheets, and excessive breakage of stay-bolts uniting the same.

I will describe the improvements as incorporated in a locomotive steam-boiler, the same being particularly advantageous in this connection, although it is not my intention to limit the invention in this respect.

I The invention is illustrated in one simple and convenient embodiment thereof in the accompanying drawings, forming a part of this specification, and in which Figure 1 is a longitudinal sectional elevation of a locomotive-boiler embodying said invention. Fig. 2 is a sectional rear elevation of the same, one half of the figure being in elevation and the other half in section. Fig. 3 is a sectional plan View of the side sheet of the fire-box and the adjacent portion of the fire-box shell.

Like characters designate corresponding parts in all thefigures of the drawings.

The fire-box is denoted in a general way by 5, and the shell by b. The lower ends of the fire-box and shell 6 are connected with a mudring 7 of copper, although other materials possessing the same characteristics as copper may be employed instead of the same. This mud-ring generally consists of four segments riveted or otherwise united to each other to form the necessary continuous structure. It will be seen that the lower end or edge of the fire-box extends short of the corresponding portion of the shell and is suitably united, as by rivets, to an upwardly-disposed flange on the inner side of the mud-ring 7, the lower edge of the shell being likewise united to a downwardly-extending flange upon the outside of said mud-ring, the latter being illustrated as approximately of ogee form in crosssection. I

The outside shell 6 includes at its rear the back head 8, which is formed upon an are at its upper end, as clearly shown in Fig. 1, having side flanges extending forwardly and downwardly and riveted to the crown-sheet '9 of'the shell and likewise connected to the side sheets 10 of said shell and also to the rear segment of the mud-ring 7. The archgd back or rear head of the exterior shell 6 a d the similarly-arched crown-sheet of box 5"are united, as will hereinafter appear. The side sheets on the shell 5 are connected together by the transverse bolts 12, this being a (30mmon way of obtaining this result.

By forming the rear end or head of the shell 6 upon an arc the expansion and contraction of the same are reduced to a minimum. Besides this a better view may be had of each other by the enginemen looking across the boiler-head of the locomotive. By making the crown-sheet of the fire-box in the form stated the direct line of expansion travel is protected, eliminating the direct longitudinal thrust from the back head of the shell, whereby travel of the stay-bolts is always reduced. Another advantage of forming the back end of the crown sheet on an arc is that the circle provides for a larger body of water and places said sheet in direct contact with the heat from the fire as it is lifted up and forward by the draft, whereby the efiiciency of the boiler is increased.

Upon the inner side of the arched rear head 8 of the exterior shell are riveted or other which arched portion, it will be observed, they are attached. The bolts 15 are squared at their threaded or lower ends in order to simplify the insertion of the same, as by reason of such construction they can be put into place from the inside of the'fire-box. The Webs of the cooperative T-bars 13 and 14 are united upon opposite sides by braces 17, arranged in pairs, the upper ends of opposite braces being rigidly fastened to the flanges of the upper T-bars, while the lower ends of said braces are connected with the lower T-bars by joints permitting relative motion of the upper portion of the shell with respect to the crown-sheet of the fire-box. This joint may be made by longitudinally slotting the lower ends of the braces to receive rivets upon the lower T-bars. The lower T-bars in each case are connected at their opposite ends by means of parallel links to the T-bars 18 near the top of the side sheets of the shell, the said connection between said lower T-bars, which, it will be remembered,are fastened to the crownsheet of the fire-box, and the side sheets of the exterior shell permitting movement of the latter with respect to the fire-box.

As the lower portion of the outer shell of the locomotive fire-box is necessarily exposed to difierent temperatures of the atmosphere than the fire-box, the result will be irregular expansion and contraction of the plates of which said shell and fire-box are composed, thus ordinarily causing strained and cracked plates,strained and broken stays,and strained seams, and hence leakage of steam and water. By virtue of the improved construction just set forth ample provision is made to overcome such expansion and contraction, whereby the disadvantages just pointed out are obviated. The side sheets of the fire-box are constructed of a plurality of vertical sections 20, spaced a suitable distance apart and connected together by what I term welts or elongated metallic channeled strips 21, extending from the mud-ring 7 to the crownsheet of the fire-box. These welts or chauneled strips 21 are located upon the inner side of the fire-box, so as not to interfere with the water-space, and their side flanges are riveted or otherwise fastened to the parallel extent.

upward and downward expansion of the several sheets, thus dividing the perpendicular travel of the fire-box side sheets and reducing the movement of the stay-bolts uniting the fire-box and shell.

Having thus described the invention, what I claim is- 1. The combination of a fire-box and an exterior shell connected therewith, the side sheets of the fire-box consisting of a plurality of plates, and the crown-sheet consisting of a single plate, and elongated strips on the inner sides of the fire-box uniting said plates longitudinally. V

2. The combination of a fire-box, an exterior shell therefor, the crownsheet of the firebox and the rear head of the shell being correspondingly arched, stay-bolts uniting said parts, bars on the inner sides of said arched head, similar bars on the outer side of the crown-sheet, braces rigidly connected with one set of bars and loosely connected with the other set of bars, and the bars on the crownsheet being loosely connected with the shell.

3. The combination of a fire-box and exte- .rior shell therefor, the crown-sheet of the firebox and the rear head of the shell being correspondingly arched, stay-bolts uniting said parts, T-bars fastened to the inside of the arched portion of the shell, corresponding T-bars below the other ones, links fixedly connected with the upper T-bars and loosely connected with the lower ones, sleeves between the lower T-bars and the outer face of the arched portion of the fire-box, and bolts passing through the lower T-bars, sleeves and upper side of the fire-box, respectively. In testimony whereof I have hereunto set my hand in presence of two subscribing witnesses.

WILLIAM II. LAUGIIRID GE.

Witnesses:

ARTHUR HEYDE, A. A. CRANE. 

